Ultrasoft Clearwater Livestock Options for Male Panduro

[MacZ]

I have some stones from Colorado that have been leaching some hardness into my blackwater tank, inching me towards neutral lately. Surely those have leached some calcium and magnesium ions,

Definitely. Limestone usually reaches equilibrium at a GH between 8 and 10° and corresponding KH. Once that is reached it curves back up after a RO waterchange within days.

I think between the two of us, we should be able to find a strategy, haha.

Yes, I think so. And maybe this will also be helpful:

Clearwater river (river type) - Wikipedia

en.wikipedia.org

When I started working with softwater the table in that article was worth pure gold.

 

[Apistonaut]

Definitely. Limestone usually reaches equilibrium at a GH between 8 and 10° and corresponding KH. Once that is reached it curves back up after a RO waterchange within days.


Yes, I think so. And maybe this will also be helpful:

Clearwater river (river type) - Wikipedia

en.wikipedia.org

When I started working with softwater the table in that article was worth pure gold.

Thanks for the chart. The clearwater is pretty nutrient poor, and I'm assuming what I've done in my blackwater tank is largely identical to Amazonian clearwater. Would a pH between 5.5-6 still be appropriate for "clearwater" if achievable? I consider the staining in my water incredibly cosmetic at this point.

 

[MacZ]

Thanks for the chart. The clearwater is pretty nutrient poor, and I'm assuming what I've done in my blackwater tank is largely identical to Amazonian clearwater. Would a pH between 5.5-6 still be appropriate for "clearwater" if achievable? I consider the staining in my water incredibly cosmetic at this point.

I'll put it this way:

The lowest readings I have achieved:
EC - 36µS/cm (measured with a standard meter)
pH - 5.3 (measured with a high grade meter I borrowed, in a sample with raised EC via addition of NaCl)
At that point the water was only lightly coloured due to the low pH and the fact I strictly limit myself to use of botanicals, no peat, no acids, sourcewater was RO (no DI), additional reduction of EC/TDS via use of Pothos.

Lowest readings I have seen measured somewhere else:
EC - 21µS/cm (standard meter)
pH - 4.3 (high grade meter)
The water was quite dark due to the owner using peat as substrate and runing RO/DI water trough a peat cannon. He also added mere drops of a stronger acid (sorry, can't remember which one), but was reluctant to chase pH because he also found EC more important.
The owner is a collector and conservation breeder of licorice gourami (Genus Parosphromenus), with about 3 dozen 20-40 Liter tanks.

And going by these experiences I doubt it's possible to replicate true blackwater in captivity and can only get as close to it as seen above. It usually will come down to this: Either you get the right EC or the right pH, but not both. Also at one point the H+ ions will raise EC again, even though pH is down to the bedrock.

 

[MacZ]

Would a pH between 5.5-6 still be appropriate for "clearwater" if achievable?

Of course. The average in clearwater is 6.5.

But I would like to underline: The distinction is not as clear cut as many people would like to think. Neither in nature, nor in the aquarium.